Electrical Conductivity Testing Lab
Build a simple circuit and test which materials conduct electricity. Metals, water, graphite — discover what lets electricity flow and what stops it cold.
What You'll Need
- 1AA battery
- 2Small LED
- 32 pieces of wire (or aluminum foil strips)
- 4Tape
- 510-12 test materials (paper clip, rubber band, coin, wooden stick, aluminum foil, plastic spoon, pencil, glass marble, wet sponge, key)
What You'll Need
A AA battery, small LED, and 2 wire pieces (or foil strips)
Tape for connections
10-12 test materials: paper clip, rubber band, coin, stick, foil, plastic spoon, pencil graphite, glass marble, wet sponge, key
How to Play
Build a circuit with a gap: battery → wire → [gap] → LED → wire → battery. LED is off.
Make a prediction chart for each material: conductor or insulator?
Bridge the gap with the paper clip. LED lights! It conducts.
Record results next to predictions.
Test all materials.
Sort into conductors and insulators.
"What do conductors have in common?"
The Science Behind It
Conductors have free electrons that can flow through the material — metals are the best examples because their atomic structure allows electrons to move easily. Insulators don't have free electrons, so they block current — rubber, plastic, wood, and glass. Pencil graphite is a fascinating conductor because it's not a metal. Water conducts when it contains dissolved minerals (tap water), but pure distilled water is actually an insulator.
Tips
The pencil graphite test is the most surprising: draw a thick dark line on paper, then touch both wire ends to the line. The LED glows dimly — graphite conducts!
Test tap water vs. distilled water if available. The difference reveals that dissolved minerals are what make water conductive.
Include some tricky items: a pencil (wood = insulator, graphite core = conductor), a painted metal surface (paint = insulator).
Ask: "Why are electrical wires covered in plastic?" (The metal inside conducts; the plastic outside insulates to keep us safe.)
Always use low-voltage batteries (AA/AAA). They're safe for handling.
Frequently Asked Questions
How long does this activity take?
This activity takes about 25 min, with 10 min of preparation time beforehand.
What materials do I need?
You'll need: aa battery, small led, 2 pieces of wire (or aluminum foil strips), tape, 10-12 test materials (paper clip, rubber band, coin, wooden stick, aluminum foil, plastic spoon, pencil, glass marble, wet sponge, key).
What age is this activity for?
This activity is designed for 8-12 years. You can adapt it for younger or older children by adjusting the complexity.
Can this be done indoors?
This activity is designed for indoor play, making it perfect for rainy days or when you're staying inside.
How difficult is this activity?
This activity has a moderate difficulty level. It may require some preparation or guidance, but is manageable for most families.
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